For building leakproof structures such as retention dikes or waste storage bins dug in a ground for example, it is necessary to ensure a sufficient seal in order to avoid for example a leak of fluids contained in the leakproof structure. A fluid leak may actually contaminate or pollute the ground.
In order to obtain a sufficient seal of the leakproof structure, geomembranes generally made for example in polyethylene or in polyvinyl are known from the prior art. Now, as a result of a poor workmanship by wear or by poor use of the geomembrane, deteriorations or holes may appear through the geomembrane thereby causing leaks. Further, the geomembrane because of its seal does not allow the discharge of gases or liquids which may stagnate or accumulate between it and the ground through a not very efficient draining web.
Document WO 00/01895 describes a geomembrane comprising a conductive layer sandwiched between two non-conductive layers. This conductive layer is laid out so as to conduct electricity and to allow detection of holes in the geomembrane by establishing a potential difference between one probe on one side of the geomembrane and the conductive layer. With this solution, it is not possible to obtain mechanical protection of the geomembrane allowing an extension of the lifetime of the geomembrane.
In the same way, document U.S. Pat. No. 5,850,144 teaches a geomembrane consisting of a metal wire-mesh between two insulating polymeric resin layers. When this geomembrane is installed, the possible holes may be detected by an electric potential applied between the metal wire-mesh and a probe. In the same way as in the preceding document, this solution does not allow mechanical protection of the geomembrane to be obtained.
Document JP 10 153516 teaches a geocomposite consisting of a conductive layer between two geotextiles. This geocomposite is intended to be positioned under a geomembrane in order to allow detections of leaks of the geomembrane. The conductive layer consists in a plate or a metal wire-mesh. This solution takes away flexibility from the geocomposite, required during its installation, and does not allow sufficient connecting contact to be obtained between the different layers of the geocomposite.